I don't have my own grain mill, so I buy my grains milled. I bought some to make a batch a few days ago, but It looks like I wont be brewing with them until right around the beginning of the new year. Will the grains still be good by then? I was planning on brewing, but I realized I don't have an empty primary at the moment!

You must remember that grain harvest comes but once a year. So the clock starts ticking when it leaves the harvester until the next years harvest. I would try to avoid using grain more than a year old. Freezing milled or unmilled grain will help retain freshness especially if you vacuum seal it.

I don't know about freezing, that messes with the structure and creates little ice crystals which are bad for many foods, so maybe it'd hurt grains too.

But I'm glad someone asked this, I often find myself paying 8 dollars a pop for shipping and I brew about twice a month. I was just afraid the premilled grain would go stale. Sounds like I can double up orders, brew one and just let one sit in grain form for a few weeks.